To activate this dialog select "Settings…" command in Options menu and click on "Compression" tab. The dialog contents are described below. Note that most of compression options can be specified via the Compression profiles/Create default button.
More details about different compression parameters can be found in How to choose optimal archiving settings topic.
In the dialog displayed after pressing this button you may specify default values for most compression options. Online help is available for all sections of the dialog, simply press "Help" button at any time to read detailed options description.
Options entered in this dialog are stored in the default compression profile, which name is "Default Profile", and are automatically restored before every archiving operation.
Some parameters of default compression profile are used not only when adding files to archive, but in other archive modification operations like deleting or renaming files. In this case WinRAR reads only those parameters, which are suitable for current operation. Extraction does not use any options from the default compression profile.
Opens the dialog to organize compression profiles. In this Organize profiles dialog you may delete existing profiles or edit their parameters. For example, you may rename a profile or set it as default. Read online help associated with this dialog for more information.
This button activates Define volume sizes dialog. Here you can customize the list of predefined volume sizes associated with "Split to volumes, size" field in Archive name and parameters dialog.
Define how to handle Enter or double click on files with archive contents and non-archive name extension in WinRAR file list in file management mode. It does not affect processing of usual archives with extensions like .rar or .zip.
Specify one or more masks separated by spaces to choose files treated as archives. All files with non-archive extensions not matching these masks will be either executed or opened in their associated programs if such programs are available. For example, if *.exe mask is not present here and you press Enter on a self-extracting exe archive in WinRAR file list, WinRAR will run this SFX archive instead of displaying its contents.
If file matches any mask, WinRAR will attempt to open it as an archive first and only if it is not an archive, it will be procesed as a usual file. This option is ignored inside of archives, so archived files are opened in associated programs on Enter.
Regardless of this option, you can always browse any archive file contents, inside or outside of archive, with standard or non-standard extension, by pressing Ctrl+PgDn on its name in WinRAR file list.